The present invention relates to an improved electronic flasher for a camera having means for automatically cutting power input to the charging circuit thereof when the device is prepared to flash and, as desired, having means for determining whether flashing is required for picture taking under the prevailing ambient conditions. The instant invention is suited to conventional cameras having built-in electronic flash units as well as cameras adapted to receive demountable flash units.
Conventionally, electronic flash units are activated or deactivated by a manual two-way switch having ON-OFF power input settings. There is a finite time lapse between the instant the devide is activated and the instant the device is charged to a condition of flash readiness. Since the device is either incapable of producing a sufficiently luminescent flash or incapable of producing any flash until adequately charged, an indicating means, such as a glow lamp is usually associated with the charging circuit thereof for the purpose of signaling when the device has reached a condition of flash readiness.
Illumination of the glow lamp is a positive indication that the high-voltage capacitor conventionally connected in the flash charging circuit has reached the given minimum condition of charge required for flashing. Retention of the minimum charge necessary for flashing these conventional devices requires continuous charging of the unit until the instant of flashing. After flashing, the charging process is immediately recommenced unless the device is shut-off.
These flasher devices are battery operated and because of their continuous mode of operation, the batteries employed therein have a short useful life. Rapid deterioration of the batteries used in these devices occurs because the devices are customarily maintained in their flash-readiness positions for long periods of time, without being flashed.
Accordingly, the flasher devices constructed according to the instant invention are provided with a power cut-off which is automatically actuated when the device is capable of being suitably flashed.